Ugdhar

From the original log you posted: Check that another minecraft server isn't running on that machine using port 25565

I don't see a crash in that log, is it the complete log? If not, try reposting it

Please post logs as described in the faq, they contain more useful information.

Please post a log as described in the FAQ, it may have more information to help.

Have him update his video drivers, from the manufacturer website, not Microsoft update, and see if that helps.

See the FAQ, cracked launchers are not supported, buy the game.

Possibly, but to be honest I don't think I've ever seen a modpack that didn't have a ton of warnings and non-fatal errors, due to poor coding and incompatibilities between mods. So is it the server or client crashing?

Is it the server or client crashing? That server log doesn't show a crash that I can see, just the client logging in and disconnecting. If the client is crashing, post that log

Please see the FAQ (https://forums.minecraftforge.net/topic/125488-rules-and-frequently-asked-questions-faq/) for how to properly post logs. Make sure you share the entire log, and not just part of it.

More information is needed to find the solution, logs, console output, and/or errors that are occurring.

Looks like you need to use a newer forge, 40.2.14, or use versions of the mods in the error that are compatible with 40.2.0

Please read the FAQ for how to post logs, pasting them inline is very hard to read. What happened after you removed JEI? A log from that run might help as well.

Please read the FAQ on how to post logs. Looks as though you have client only mods trying to load on a server. Remove them and give it another try

"in neruina-common.mixins.json:PlayerInventoryMixin from mod neruina failed injection check" If you remove nerunia does it still crash?

Try jarfix (provided you indeed have java installed)

You should post full logs as per the FAQ (https://forums.minecraftforge.net/topic/125488-rules-and-frequently-asked-questions-faq/)

If you delete (make a backup just in case) the config file mentioned in the error, does it load?

Does it work if you use the regular Minecraft launcher? Also, please read the FAQ about how to post logs, pasting your log directly into your forums post makes it hard to read, and makes the post pages and pages long.

If you add 1 mod, does it crash? If you change which 1 mod you add, does it still crash? Which mods are you adding? What modpack are you starting from? A log from adding 1 mod and having it crash might possibly be helpful as well. It is entirely possible the mods you're adding are incompatible with other mods in the pack, or the way the pack is configured.

These forums are for Minecraft Forge, not Fabric. Your question would be better asked where Fabric support is given, likely their discord server.

These forums are for Minecraft Forge, not Fabric. Your question would be better asked where Fabric support is given, quite likely their discord channel.

Please read the FAQ about how to properly post your logs, it makes it easier for people to help you. Remove those extra mods, then add them back a couple at a time, testing in between. This will allow you to determine which mod you are adding that is broken/incompatible.

These forums are for Minecraft Forge, not Fabric. You would probably be better served posting this question wherever fabric support is given, most likely their discord server.

Please read the FAQ on how to post your logs; embedding them in your post like that makes them very hard to read, which may make it harder for people to help you. I'd be interested to know if you run into the same problem(s) if you create a fresh world, vs loading into the one you've been playing.

https://forums.minecraftforge.net/topic/125488-rules-and-frequently-asked-questions-faq/